There is a variety of available one way coupling designs adapted to specific needs. Such couplings typically include a rotatable member for connection with a shaft of a driven machine and at least one rotatably stationary member to prevent rotation of the rotatable member in one direction or to provide a driving connection with, for example, a standby drive under certain circumstances. Such couplings find use in a variety of applications and frequently must function under extremely adverse conditions.
Lubrication is an extremely difficult problem in some applications. Some large couplings have an external lubricant pump which operates satisfactorily as long as the pump and related equipment is functioning properly. One shortcoming with previous coupling designs using an external lubricant supply is their limited ability to operate satisfactorily when such supply is terminated. This is a serious shortcoming because loss of lubricant often occurs when the coupling is subjected to other difficult operating conditions.
Couplings having internal pumping systems have also been used to supplement or replace external pumps. Many of these designs incorporate scoops or tubes which extend into a lubricant reservoir. Efficiency problems have been created by such systems because of the rotational drag forces existant with those designs, often accompanied by unacceptable lubricant turbulence in the reservoir.
It is the object of the present invention to provide a standby and/or holdback coupling with a simple compact and efficient internal lubricant circulation system.